24-h Sodium Research Articles

Abstract P378: Impaired Diurnal Control of Blood Pressure and Sodium Excretion in Aged Hypertensive Male Sprague Dawley Rats

Hypothesis: The diurnal rhythmicity of blood pressure (BP) and sodium excretion is important to blood pressure regulation and is strongly influenced by the circadian clock genes. We hypothesized that the diurnal control of BP and natriuresis is impaired in aged male Sprague Dawley (SD) rats and may be associated with altered kidney expression of circadian clock gene proteins. Methods: Radiotelemetry (to record mean arterial BP (MAP)) and metabolic balance (to assess sodium excretion) was conducted in 3-month-old (3M) and 16-month-old (16M) male SD rats. On a separate day, 3M and 16M rats received an acute 900 μEq NaCl load by oral gavage at ZT0 and sodium excretion was assessed. Total renal cortex expression of Per1 and Bmal1 was assessed by immunoblotting (N=4-6/group ± SD). Results: 16M rats exhibit significantly increased MAP and 24-h sodium retention vs. 3M rats [MAP (mmHg) 3M 102±4 vs. 16M 127±5, P<0.05; 24h Na retention (mEq/24h) 3M 0.3±0.1 vs. 16M 0.8±0.2, P<0.05). 16M rats exhibit an attenuation of the circadian MAP pattern compared to 3M rats. Aged rats have a significant decrease in the blood pressure rise during the dark (active) vs. 3M rats (Dark phase increase in MAP (mmHg) 3M +13.6±2.1 vs. 16M +4.8±1.9, P<0.05). 3M rats exhibit a classical diurnal pattern of 24-h sodium excretion with increased natriuresis during the dark (active) phase – a response that is attenuated in 16M rats that exhibit a significant reduction in the increase in natriuresis in the dark phase (Light phase UNaV (μEq/12h) 3M 380±48 vs. 16M 410±36, Dark phase natriuresis 3M 620±31 vs 16M 502±27, P<0.05). 16M rats had an impaired natriuretic response to an acute oral NaCl load in the first 12h post-gavage (UNaV 12h (μEq/12h) 3M 681±42 vs. 16M 243±39, P<0.05). In 16M old rats there was no change in renal Per1 and decreased renal Bmal1 protein (Bmal1 fold change 16M vs. 3M, 0.65±0.7, P<0.05). Conclusions: We observed impaired circadian control of blood pressure and renal sodium excretion in aged male SD rats. These changes in renal sodium handling may reflect endogenous decreases in renal Bmal1 levels with age and contribute to the observed hypertensive phenotype in aged rats.

Prediction of post-donation renal function using machine learning techniques and conventional regression models in living kidney donors.

Accurate prediction of renal function following kidney donation and careful selection of living donors are essential for living-kidney donation programs. We aimed to develop a prediction model for post-donation renal function following living kidney donation using machine learning. This retrospective cohort study was conducted with 823 living kidney donors between 2009 and 2020. The dataset was randomly split into training (80%) and test sets (20%). The main outcome was the post-donation estimated glomerular filtration rate (eGFR) 12months after nephrectomy. We compared the performance of machine learning techniques, traditional regression models, and models from previous studies. The best-performing model was selected based on the mean absolute error (MAE) and root mean square error (RMSE). The mean age of the participants was 45.2 ± 12.3years, and 48.4% were males. The mean pre-donation and post-donation eGFRs were 101.3 ± 13.0and 68.8 ± 12.7mL/min/1.73m2, respectively. The XGBoost model with the eGFR, age, serum creatinine, 24-h urine creatinine, 24-h urine sodium, creatinine clearance, cystatin C, cystatin C-based eGFR, computed tomography volume of the remaining kidney/body weight, normalized GFR of the remaining kidney measured through a diethylenetriaminepentaacetic acid scan, and sex, showed the best performance with a mean absolute error of 6.23 and root mean square error of 8.06. An easy-to-use web application titled Kidney Donation with Nephrologic Intelligence (KDNI) was developed. The prediction model using XGBoost accurately predicted the post-donation eGFR after living kidney donation. This model can be applied in clinical practice using KDNI, the developed web application.

Inadequate Dietary Education and Poor Adherence to a High Protein, Low Sodium Diet in Cirrhosis: Mixed Methods Approach.

Malnutrition in cirrhosis is associated with poor outcomes, leading to guidelines for a high protein, low sodium diet; however, there is no guidance regarding the implementation of diet education in clinical practice. A mixed methods study enrolled 21 patients with cirrhosis and their caregivers. Semi-structured interviews on barriers and facilitators of dietary education and adherence were conducted. Demographic and clinical data were obtained, along with quantitative measures of dietary adherence, including 24-h food recall and spot urine sodium. Combined deductive and inductive coding was used to identify qualitative themes, along with a quantitative assessment of interviews. Quantitative data was reported using descriptive statistics with frequencies, mean and confidence intervals. Participants were mostly male (16/21) with a mean age 57.8years (SE 2.8) and MELD-Na 9 (SE 1.2). 4 themes emerged: 1. More than 50% of participants and caregivers endorsed no or inadequate diet education 2. They reported mostly negative experiences with dietary adherence with largest impact on social life 3. Facilitators of adherence included the presence of household support and fear of complications of cirrhosis 4. Overwhelmingly desired non-generic handouts and information. Dietary adherence was poor with only one participant meeting protein and sodium requirements based on food recall. Four participants who adhered to < 2000mg sodium had inadequate daily caloric intake. Dietary education is inadequate, and adherence to dietary recommendations is poor in patients with cirrhosis. Future studies should use these barriers and facilitators for intervention development.

The impact of high-salt diet on asthma in humans and mice: Effect on specific T-cell signatures and microbiome.

The rise in asthma has been linked to different environmental and lifestyle factors including dietary habits. Whether dietary salt contributes to asthma incidence, remains controversial. We aimed to investigate the impact of higher salt intake on asthma incidence in humans and to evaluate underlying mechanisms using mouse models. Epidemiological research was conducted using the UK Biobank Resource. Data were obtained from 42,976 participants with a history of allergies. 24-h sodium excretion was estimated from spot urine, and its association with asthma incidence was assessed by Cox regression, adjusting for relevant covariates. For mechanistic studies, a mouse model of mite-induced allergic airway inflammation (AAI) fed with high-salt diet (HSD) or normal-salt chow was used to characterize disease development. The microbiome of lung and feces (as proxy for gut) was analyzed via 16S rRNA gene based metabarcoding approach. In humans, urinary sodium excretion was directly associated with asthma incidence among females but not among males. HSD-fed female mice displayed an aggravated AAI characterized by increased levels of total IgE, a TH2-TH17-biased inflammatory cell infiltration accompanied by upregulation of osmosensitive stress genes. HSD induced distinct changes in serum short chain fatty acids and in both gut and lung microbiome, with a lower Bacteroidetes to Firmicutes ratio and decreased Lactobacillus relative abundance in the gut, and enriched members of Gammaproteobacteria in the lung. High dietary salt consumption correlates with asthma incidence in female adults with a history of allergies. Female mice revealed HSD-induced T-cell lung profiles accompanied by alterations of gut and lung microbiome.

Development and preliminary validation of a prediction formula of sodium and sodium-to-potassium ratio based on multiple regression using 24-h urines

Accurate measurement of sodium intake in the diet is challenging, and epidemiological studies can be hampered by the attenuation of associations due to measurement error in sodium intake. A prediction formula for habitual 24-h urine sodium excretion and sodium-to-potassium ratio might lead to more reliable conclusions. Five 24-h urinary samples and two Food Frequency Questionnaires (FFQs) were conducted among 244 Japanese participants aged 35–80 years. We conducted multivariate linear regression analysis with urinary excretion as dependent variables and eating behaviour and food frequency as independent variables. Empirical weights of sodium excretion and sodium-to-potassium ratio were extracted. Preliminary validity was also assessed by randomly dividing the subjects into development and validation groups based on the correlation coefficient between estimates by the prediction formula and urinary excretion. Taste preference, soy sauce use at the table, frequency of pickled vegetables intake and number of bowls of miso soup were extracted as determinants of sodium excretion. Correlation coefficients between the estimates and urinary excretion for men and women were 0.42 and 0.43, respectively, for sodium and 0.49 and 0.50, respectively, for sodium-to-potassium ratio. This prediction formula may provide more accurate estimation of sodium intake and sodium-to-potassium ratio than the food composition approach.

Comparison of central diabetes insipidus (antidiuretic hormone deficiency) and stalk effect in patients with adamantinomatous and papillary craniopharyngioma.

Craniopharyngioma (CP), a rare benign intracranial tumor, is still a major clinical challenge. There are two major histologic phenotypes: papillary CP (PCP) and adamantinomatous CP (ACP). This research aimed to assess the occurrence of central diabetes insipidus (antidiuretic hormone deficiency), the level of prolactin, and the stalk effect between PCP and ACP subtypes prior to and after surgery. Clinical data of CP patients before and after surgical resection of the tumor were analyzed retrospectively. These patients were divided into PCP and ACP groups, in accordance with the pathologic classification. The data of prolactin level, 24-h urinary volume, urine specific gravity and electrolyte status before and after surgery were evaluated in these two CP subtypes. A total of 86 CP patients were included, among which 28 patients were PCP and 58 were ACP. Compared to those prior to surgery, 24-h urine volume, serum sodium and serum chlorine concentrations were obviously increased, while prolactin and urine specific gravity were remarkably decreased in all the CP patients after surgery. Compared to those before operation, prolactin level and urine specific gravity were decreased, and 24-h urine volume, serum sodium and serum chlorine were elevated after operation in ACP patients. Moreover, after surgery, 24-h urine volume in PCP patients was higher than that in ACP group. The central diabetes insipidus in patients with CP was aggravated after surgical resection, especially in ACP patients. Moreover, the central diabetes insipidus of PCP subtype was more serious than that of ACP subtype.

Estimation of dietary intake of sodium, potassium, phosphorus and protein in healthy Indian population and patients with chronic kidney disease.

Poor nutritious diet is a major risk element for non-communicable diseases (NCD), which are of considerable public health concern. Given the diverse dietary patterns in India, precise determination of nutrient consumption is crucial for disease management. The present study assessed the dietary intake of sodium, potassium, protein, and phosphorus among North Indians. This cross-sectional study included healthy adults and adults with stage 2 to 4 chronic kidney disease (CKD). We analysed sodium, protein, potassium and phosphorus intakes using one-time 24-h urinary excretion. Dietary intake was also analysed in subgroups based on sex, body mass index, blood pressure and abdominal obesity. We evaluated the performance of various equations available to estimate sodium intake using a spot urine sample with respect to the sodium excretion measured in a 24-h urine sample. Descriptive statistics was used along with t-test for statistical significance. A total of 404 subjects (182 adult healthy subjects and 222 adults with CKD) with a mean age of 47.01 ± 11.46 years were studied. Mean dietary intakes of sodium, salt, potassium, protein and phosphorus were 2.94 ± 1.68 g/day, 7.42 ± 4.24 g/day, 1.43 ± 0.59 g/day, 47.67 ± 14.73 g/day and 0.86 ± 0.39 g/day, respectively. There were no differences in nutrient consumption between adults who were healthy and those with CKD. Consumption of sodium, salt, protein, potassium, and phosphorus among healthy population vs. those with CKD were 2.81 ± 1.60 vs. 3.05 ± 1.73 g/day (p = 0.152), 7.08 ± 4.04 vs. 7.70 ± 4.37 g/day (p = 0.143), 47.16 ± 14.59 vs. 48.08 ± 14.86 g/day (p = 0.532), 1.38 ± 0.59 vs. 1.48 ± 0.58 g/day (p = 0.087) and 0.86 ± 0.41 vs. 0.87 ± 0.37 g/day (p = 0.738), respectively. Men had higher consumption of these nutrients than women. Compared to non-hypertensives, hypertensive subjects had higher consumption of salt (8.23 ± 4.89 vs. 6.84 ± 3.59 g/day, p = 0.002) and potassium (1.51 ± 0.63 vs. 1.38 ± 0.55 g/day, p = 0.024), however, no difference were found in protein and phosphorus intakes. In terms of performance of equations used to estimate 24-h sodium intake from spot urinary sodium concentration against the measured 24-h urinary sodium excretion, INTERSALT 2 equation exhibited the least bias [1.08 (95% CI, -5.50 to 7.66)]. The study shows higher-than-recommended salt and lower-than-recommended potassium intake in the north Indian population compared to those recommended by guidelines. The dietary protein intake is below the recommended dietary allowance. These findings help the development of targeted policies for dietary modification to reduce the risk of the development and progression of CKD.

The contribution of sodium reduction and potassium increase to the blood pressure lowering observed in the Salt Substitute and Stroke Study.

The Salt Substitute and Stroke Study (SSaSS) demonstrated significant reductions in systolic blood pressure (SBP), and the risk of stroke, major cardiovascular events and total mortality with the use of potassium-enriched salt. The contribution of sodium reduction versus potassium increase to these effects is unknown. We identified four different data sources describing the association between sodium reduction, potassium supplementation and change in SBP. We then fitted a series of models to estimate the SBP reductions expected for the differences in sodium and potassium intake in SSaSS, derived from 24-h urine collections. The proportions of the SBP reduction separately attributable to sodium reduction and potassium supplementation were calculated. The observed SBP reduction in SSaSS was -3.3 mmHg with a corresponding mean 15.2 mmol reduction in 24-h sodium excretion and a mean 20.6 mmol increase in 24-h potassium excretion. Assuming 90% of dietary sodium intake and 70% of dietary potassium intake were excreted through urine, the models projected falls in SBP of between -1.67 (95% confidence interval: -4.06 to +0.73) mmHg and -5.33 (95% confidence interval: -8.58 to -2.08) mmHg. The estimated proportional contribution of sodium reduction to the SBP fall ranged between 12 and 39% for the different models fitted. Sensitivity analyses assuming different proportional urinary excretion of dietary sodium and potassium intake showed similar results. In every model, the majority of the SBP lowering effect in SSaSS was estimated to be attributable to the increase in dietary potassium rather than the fall in dietary sodium.

No change in 24-h sodium intake estimated from spot urine in Norwegian adults from 2006 to 2019: the population-based Trøndelag Health Study (HUNT).

Monitoring time trends in salt consumption is important for evaluating the impact of salt reduction initiatives on public health outcomes. There has so far not been available data to indicate if salt consumption in Norway has changed during the previous decade. We aimed to assess whether average 24-h salt intake estimated from spot urine samples in the adult population of mid-Norway changed from 2006-2008 to 2017-2019 and to describe variations by sex, age and educational level. Repeated cross-sectional studies. The population-based Trøndelag Health Study (HUNT). In each of two consecutive waves (HUNT3: 2006-2008 and HUNT4: 2017-2019), spot urine samples were collected from 500 men and women aged 25-64 years, in addition to 250 men and women aged 70-79 years in HUNT4. Based on spot urine concentrations of Na, K and creatinine and age, sex and BMI, we estimated 24-h Na intake using the International Cooperative Study on Salt and Blood Pressure (INTERSALT) equation for the Northern European region. Mean (95 % CI) estimated 24-h salt intakes in men were 11·1 (95 % CI 10·8, 11·3) g in HUNT3 and 10·9 (95 % CI 10·6, 11·1) g in HUNT4, P = 0·25. Corresponding values in women were 7·7 (95 % CI 7·5, 7·9) g and 7·7 (95 % CI 7·5, 7·9) g, P = 0·88. Mean estimated salt intake in HUNT4 decreased with increasing age in women, but not in men, and it did not differ significantly across educational level in either sex. Estimated 24-h salt intake in adult men and women in mid-Norway did not change from 2006-2008 to 2017-2019.

Experience with 2 years’ intervention to progressively reduce salt supply to kitchens in elderly care facilities—challenges and further research: post hoc analysis of the DECIDE-Salt randomized clinical trial

BackgroundProgressive reduction of sodium intake is an attractive approach for addressing excessive salt intake, but evidence for this strategy in real practice is limited. We aimed to determine the feasibility, effectiveness, and safety of a progressive sodium intake reduction intervention in real-world setting.MethodsWe randomized 48 residential elderly care facilities in China, with 1612 participants aged 55 years and older, to either progressive reduction (PR, 24 facilities) or no reduction (NR, 24 facilities) of the supply of study salt to the kitchens of these facilities for 2 years. The primary efficacy outcome was systolic blood pressure (SBP) at any scheduled follow-up visit. Secondary efficacy outcomes included diastolic blood pressure (DBP) at any scheduled follow-up visit, and major adverse cardiovascular events (comprising non-fatal stroke, non-fatal myocardial infarction, hospitalized non-fatal heart failure, or vascular death) and total mortality. The perception of food saltiness, the addition of out-of-study salt in meals, and 24-h urinary sodium excretion were used as process indicators.ResultsPre-specified analysis per randomization found no effect of the intervention on the 2-year overall mean systolic and diastolic blood pressure (SBP, DBP) and any other outcomes. However, post hoc analysis showed that the intervention effect on blood pressure varied over multiple follow-up visits (p for interaction < 0.046) and presented favorable differences at the 24-month visit (SBP = − 3.0 mmHg, 95%CI = − 5.6, − 0.5; p = 0.020; DBP = − 2.0 mmHg, 95%CI − 3.4, − 0.63; p = 0.004). The effect on 24-h sodium was non-significant (− 8.4 mmol, 95%CI = − 21.8 to 4.9, p = 0.216), though fewer participants with NR than with PR reported food tasting bland (odds ratio 0.46; 95%CI 0.29 to 0.73; p = 0.001). Reporting of bland food taste and other process measures indicated that intervention delivery and adherence were not fully achieved as designed.ConclusionsThe experience of this real-world study demonstrated that achieving acceptability and sustainability of the progressive sodium intake reduction strategy among older adults was challenging, but it has shown potential for effectiveness in these and potentially other residential settings if the lessons of DECIDE-Salt are applied in further studies.Trial registrationClinicalTrials.gov (NCT03290716).

A Case Report of an Effective Treatment for Syndrome of Inappropriate Secretion of Antidiuretic Hormone with Integration of Western Medicine and Traditional Chinese Medicine

Background: Syndrome of Inappropriate secretion of Antidiuretic Hormone (SIADH) is a group of disorders in which free water excretion is impaired due to increased Arginine Vaso Pressin (AVP) secretion in the absence of renal or endocrine dysfunction, which in turn leads to hypotonic hyponatremia. In this case report, we describe the diagnostic process of a patient with SIADH and the treatment with integration of Western and Chinese medicine. Case Presentation: A 69-year-old man was admitted to our hospital for intermittent hand tremors. He was diagnosed with hyponatremia based on laboratory tests. However, after 2 weeks of sodium supplementation, his condition did not improve. Combined with Pituitary MRI, 24h urine sodium and other laboratory tests, he was diagnosed with SIADH. After taking oral tolvaptan and traditional Chinese medicine Rehmanniae Decoction of Six Ingredients granules, his symptoms were alleviated and the serum sodium normalized. Conclusion: SIADH could be as an etiology for hyponatremia that is difficult-to-correct, and traditional Chinese medicine may have some efficacy and advantages.

Effectiveness of a Smartphone Application for Dietary Sodium Intake Measurement.

Accurate estimation of sodium intake is a key requirement for evaluating the efficacy of interventional strategies to reduce salt intake. The effectiveness of a smartphone application in measuring dietary sodium intake was assessed. This study included 46 participants who consented to register in Noom's food-logging program. All participants were followed up for six months from the day of enrollment. The mean age of the participants was 40.2 ± 12.3 years, and 22 (48%) participants were male. The average number of times/weeks the meals were logged was 16.2 ± 10.3. At baseline, the mean 24-h urine sodium was 124.3 mmol/24 h. The mean sodium intake measured by the smartphone application and calculated using the 24-h urine sodium was 2020.9 mg/24 h and 2857.6 mg/24 h, respectively. During the second visit, the mean 24-h urine sodium was 117.4 mmol/24 h. The mean sodium intake measured by the smartphone application and calculated using the 24-h urine sodium was 1456.0 mg/24 h and 2698.3 mg/24 h, respectively. Sodium intake measured using the smartphone application positively correlated with that calculated using the 24-h urine sodium at baseline (r = 0.464; p < 0.001) and follow-up (r = 0.334; p= 0.023). Dietary sodium intake measured using a smartphone application correlated well with that estimated using 24-h urine sodium level.

Is a spot urine sample a good substitution to estimate 24-h urinary sodium excretion in a population ≥ 50years old? A validation study.

A variety of prediction equations have been able to estimate 24-h urinary sodium excretion from spot urine samples; however, Iranians over the age of 50 have not been compared and verified. Using spot urine samples as a substitute for 24-h urine samples to estimate 24-h urine sodium excretion among the population age 50 and older are the purpose of this study. A 24-h urinary sodium excretion was studied by well-known Kawasaki, INTERSALT, Tanaka, and World Health Organization/Pan American Health Organization (WHO/PAHO) formulas. On 360 individuals, the mean bias, agreements between estimated and measured values, correlation, absolute and relative differences, and misclassification rates were evaluated for four equations. As a result, the mean urinary sodium excretion for a 24-h period was 136.3 ± 52.21mmol/24-h, which corresponds to a calculated intake of 9.1 ± 3.8g of salt per day. According to the WHO/PAHO formula, the mean bias between measured values and estimated 24-h urinary sodium excretion is - 21.6mg/day (95% confidence interval (CI) - 144.8, 101.6mg/day), which is the smallest difference compared with the other three formulas. The lowest rate of individual misclassification of salt intake was 40% for WHO/PAHO, especially for those who consumed less than 9g/day, while Kawasaki had the lowest misclassification rate at higher levels of salt intake. As a result of our research, the WHO/PAHO equations accurately predict 24-h urinary sodium excretion among Iranians aged ≥ 50 more than other equations, both at the population level and at the individual level. However, further study is needed in regard to different ages in Iran.

Assessment of metabolic risk factors for nephrolithiasis in patients with autosomal dominant polycystic kidney disease: a cross-sectional study.

Nephrolithiasis is more common in autosomal dominant polycystic kidney disease (ADPKD) than in the normal population. We aimed to investigate the anatomical and metabolic factors that may be associated with nephrolithiasis in patients with ADPKD METHODS: In this cross-sectional study, a total of 180 participants were included. Eighty-five patients with ADPKD [42 patients with nephrolithiasis (PKD N +) and 43 without nephrolithiasis (PKD N -)] were recruited. Forty-seven nephrolithiasis patients without ADPKD (N) and 48 healthy controls (HC) were selected as control groups. 24-h urine collections were measured in all participants. 24-h urine citrate, calcium, urate, oxalate, magnesium and sodium, serum electrolytes, and eGFRs were compared. Total kidney volumes were not different between patients with PKD N + and PKD N -. Hypocitraturia was common in all patients with ADPKD (69.4%), and it was not different between PKD N + (76.2%) and PKD N- (62.8%). However, hypocitraturia was statistically higher in PKD N + and PKD N - than in N (38.3%) and HC (12.5%) (p<0.05). 24-h urine calcium, urate, and oxalate levels were similar between PKD N + and PKD N - CONCLUSIONS: Hypocitraturia was found to be significantly higher in patients with ADPKD than in healthy adults and other kidney stone patients.

Efficacy of an Educational Intervention for Sodium Restriction in Patients with Hypertension: A Randomized Controlled Trial

There is sound evidence showing the efficacy of non-pharmacological interventions in lowering blood pressure (BP); however, adherence is usually poor. Interventions to induce behavioral changes aim to improve the ability to read labels, choose foods, and eat low-sodium meals, reinforcing adherence to sodium restriction. In this randomized parallel-controlled trial, we assessed the effectiveness of an educational intervention using the Dietary Sodium Restriction Questionnaire (DSRQ) scores. A follow-up period of 6 months was conducted. Participants were randomized into (1) an educational intervention provided by a registered dietitian on individual visits and dietary planning; (2) a control group with the usual care and dietary recommendations. Patients underwent 24-h ambulatory BP monitoring, 12-h fasting blood tests, spot urine collection, and assessment using DSRQ. We randomized 120 participants (67.5% women and 68.3% Caucasians), and 25 participants were lost to follow-up. The 24-h sodium urinary excretion changed in the control (Δ −1610 mg/day; 95% confidence interval [CI] −1800 to −1410) and intervention groups (Δ −1670 mg/day; 95% CI −1800 to −1450) over time. There was no significant difference in the 24-h estimated sodium between groups. In hypertensive patients, DSRQ-based educational intervention is effective for improving the ability to detect and overcome obstacles to a low-sodium restriction diet but is as effective as dietary recommendations for lowering sodium.

Voided volume may not impact stone outcomes: Review of a large institutional nephrolithiasis cohort.

Urologic guidelines universally recommend increasing fluid intake for kidney stone prevention. Increased voided volume is thought to help reduce stone recurrence and severity, but supporting evidence is limited. Nephrolithiasis outcomes and 24-h urine data for patients from the Registry for Stones of the Kidney and Ureter (ReSKU), a registry of nephrolithiasis patients collected between 2015 and 2020, were retrospectively analysed. Outcome was stone events, either an office visit where a patient reports symptomatic passage of stones or surgery for stone removal. We identified 450 stone patients with 24-h urine and kidney stone outcome data. There was no significant difference in 24-h voided volume between patients with one stone event and patients with two or more stone events. On multivariable logistic regression, after controlling for age, gender, BMI, and 24-h sodium and creatinine per kilogram, no significant associations were found between voided volume and stone events. There was a statistically significant negative correlation noted between voided volume and stone events in calcium oxalate dihydrate stone formers (Spearman R= -0.42, p= 0.04), but not others. Twenty-four-hour voided volume was not associated with stone events in a large institutional cohort, and subset analysis reveals that some stone formers may benefit more from increased voided volume than others; identifying such patients represents a novel precision medicine opportunity.

The association between sodium intake and coronary and carotid atherosclerosis in the general Swedish population.

A high intake of salt raises blood pressure and the risk of cardiovascular disease. Previous studies have reported on the association between salt intake and carotid stenosis, but the association with coronary atherosclerosis has not been reported. Therefore, this project aimed at studying the association between salt intake and both carotid and coronary atherosclerosis in a contemporary community-based cohort. Estimated 24-h sodium excretion (est24hNa) was calculated by the Kawasaki formula for participants of two sites (Uppsala and Malmö) of the Swedish Cardiopulmonary bioImage Study, who underwent a coronary computed tomography (n = 9623) and measurement of coronary artery calcium score (CACS, n = 10 289). Carotid ultrasound was used to detect carotid plaques (n = 10 700). Ordered logistic regression was used to calculate odds ratios (OR) per 1000 mg increase in est24hNa. We also investigated potential J-formed associations using quintiles of est24hNa. Increased est24hNa was associated with increased occurrence of carotid plaques [OR: 1.09, P < 0.001, confidence interval (CI): 1.06-1.12], higher CACS (OR: 1.16, P < 0.001, CI: 1.12-1.19), and coronary artery stenosis (OR: 1.17, P < 0.001, CI: 1.13-1.20) in minimal adjusted models. Associations were abolished when adjusting for blood pressure. When adjusting for established cardiovascular risk factors (not including blood pressure), associations remained for carotid plaques but not for coronary atherosclerosis. There was no evidence of J-formed associations. Higher est24hNa was associated with both coronary and carotid atherosclerosis in minimal adjusted models. The association seemed mainly mediated by blood pressure but to some degree also influenced by other established cardiovascular risk factors.

Dietary counselling to reduce moderate sodium intake: effects on cardiovascular and renal biomarkers: primary findings of the COSIP and STICK phase II feasibility randomised controlled trials.

While low sodium intake (<2.3g/day) is recommended, there is uncertainty about long-term feasibility and effects on cardiorenal biomarkers in populations with moderate intake. In two phase IIb, feasibility, randomised, parallel, open-label, controlled, single-centre trials, individuals aged >40 years with stable blood pressure (BP), without heart failure or postural hypotension were randomised to intensive dietary counselling (target sodium intake <2.3g/day) or usual care between March 2016 and July 2018. One trial included participants with chronic kidney disease (CKD); the other excluded those with CKD or cardiovascular disease. All participants received healthy eating advice. Primary outcomes were NT-pro B-type natriuretic peptide (NT-proBNP), high sensitivity troponin T (hsTnT), C-reactive protein (CRP), renin, aldosterone and, creatinine clearance (CrCl) at 2-years. These trials are registered with ClinicalTrials.gov, STICK trial (NCT02458248) and COSIP trial (NCT02738736). 373 participants, with mean 24-h urine sodium 3.16±1.47g/day, were randomised to intervention (n=187) or usual care (n=186). At 3-months, the intervention reduced 24-h urine sodium (intervention-0.11g/day, usual care+0.28g/day, p=0.003), BP (systolic-2.52mmHg, p=0.05; diastolic-1.92, p=0.02) and increased renin (+33.35 mIU/L [95%CI 3.78-62.91]). At 2-years, the intervention significantly reduced self-reported salt use (p<0.001), but not 24-h urine sodium (intervention-0.23g/day, usual care+0.05g/day, p=0.47). At 2-years, there were no significant between-group differences in BP (systolic p=0.66; diastolic p=0.09), NT-proBNP (p=0.68), hsTnT (p=0.20), CRP (p=0.56), renin (p=0.52), aldosterone (p=0.61), or CrCl (p=0.68). Among individuals with moderate sodium intake, intensive dietary counselling resulted in small short-term reductions in sodium intake and BP, but no significant effect on sodium intake, BP, or cardiorenal biomarkers at two years. Our trial suggests that it may not feasible to reduce sodium sustainably in those with a sodium intake around 3.0g/day, through an intensive dietary counselling intervention. The STICK trial was funded by the Health Research Board of Ireland and the COSIP trial was funded by the European Research Council.

Validation of a Thai semiquantitative food frequency questionnaire (semi-FFQ) for people at risk of metabolic syndrome

BackgroundFood frequency questionnaires (FFQ) are a useful dietary assessment tool to determine relationships between diet and non-communicable diseases (NCDs). Our purpose was to validate a semiquantitative FFQ (semi-FFQ) for Thais at risk of metabolic syndrome (MS).MethodsThe researchers identified 345 men and women aged 30–65 years who were eligible for the study. Ninety-four participants were finally enrolled (54 in a “urine-collection not-required” group and 40 in a “urine collection” group). They were asked to maintain a 4-day food record for 4 weeks and partook in a semi-FFQ interview during week 4. Urine samples and biochemical results related to MS were collected. Validation results were associated with three primary nutrients for MS (sugar, fat, and sodium) and biochemical results (blood glucose, lipid profiles, blood pressure, and 24-h urine sodium).ResultsThe biomarker level of each key MS nutrient significantly increased commensurate with rises in semi-FFQ estimated intakes. Correlation coefficients (r) were as follows: fasting blood glucose, r = 0.221 (fruits) and r = 0.229 (desserts); triglycerides, r = 0.112 (a la carte-dishes); low-density lipoprotein cholesterol, r = 0.205 (rice-with-topping dishes); systolic blood pressure, r = 0.272 (snacks) and r = 0.190 (a la carte dishes). Fasting blood glucose was a significant biomarker associated with the development of metabolic syndrome (OR 1.42, 95% CI 1.12–1.81). We also found that fat (OR 1.28, 95% CI 1.09–1.89), sodium (OR 1.98, 95% CI 1.05–1.95) and energy (OR 1.09, 95% CI 1.01–1.17) from an a la carte meal were significantly associated with the development of metabolic syndrome.ConclusionsThai food has a unique characteristic since it often pairs various ingredients and seasoning in one menu. This semi-FFQ is a tool that offers relatively valid ranking for intake of energy, nutrients, single foods, and mixed dishes based on Thai menus associated with a risk for developing metabolic syndrome and NCDs. Using this tool could help identify unhealthy dietary patterns and help develop recommendations for people at risk with the goal of preventing NCDs.

Validation of spot urine in estimating 24-h urinary sodium, potassium and sodium-to-potassium ratio during three different sodium diets in healthy adults

Purpose To evaluate the validity of spot urine assay methods in estimating the 24-h urinary sodium, potassium and sodium-to-potassium ratio during three different sodium diets. Materials and methods Twelve healthy volunteers were asked to adhere to 3 dietary sodium targets (3.3–5.0g/day,<3.3 g/day and >5.0 g/day) for three consecutive weeks and to measure salt excretion daily in spot urine samples using a self-monitoring device. On day 7 of each week, 24-h urine was collected to compare measured with estimated 24-h salt excretion (by the Kawasaki, Tanaka and INTERSALT equations). Results Correlation coefficients relating measured and estimated 24-h sodium excretion were low and not significant for Kawasaki and INTERSALT and moderate for the Tanaka equation (τ 0.56–0.64,p<.05). Bland–Altman plots showed considerable differences between estimated and measured sodium excretion across all salt diets. Over 40% of the participants showed an absolute difference between measured and estimated 24-h sodium of more than 1000 mg/day. The correlation coefficients between 24-h and spot Na/K ratio were 0.67, 0.94 and 0.85(p<.05), and mean differences were 0.59, 0.06 and 0.48 for the intermediate, low and high sodium diets, respectively. Conclusion These findings do not support estimation of individual 24-h salt excretion from spot urine by the Kawasaki, Tanaka, or INTERSALT formula.